Dermatone cutting blade assembly

ABSTRACT

A blade assembly designed for use in dermatone or skin grafting instruments in which the blade assembly is mounted on an oscillatory carrier, the blade assembly embodying a support or platform member of molded plastic to the forward edge portion of which is secured a metal blade element having a forward cutting edge, the support member having on its upper surface a plurality of raised ribs extending back at right angles to the cutting edge, the ribs serving to reinforce and give rigidity to the plastic support member and to guide and reduce the friction of engagement of the skin with the blade assembly, and the plastic support member having formed integrally therewith studs which in the assembly extend down through the blade element and are riveted over and avoid any projecting ends which could interfere with the free advance of the skin.

Stevens, II

[ Dec. 31, 1974 DERMATONE CUTTING BLADE ASSEMBLY [75] Inventor: William Henry Stevens, II,

Staunton, Va.

[73] Assignee: Philip Morris Incorporated, New

York, NY.

[22] Filed: May 23, 1973 [21] Appl. No.: 362,956

[52] US. Cl 30/344, 30/348, 30/349, 30/351, 83/9155 [51] Int. Cl. B25g 3/36 [58] Field of Search 30/343, 344, 260, 349, 30/346.58, 346.59, 346.6, 346.61, 348, 351; 83/9155 [56] References Cited UNITED STATES PATENTS 78,887 6/1868 Fraser 30/348 596,530 1/1898 McCoy 30/349 2,045,184 6/1936 Gaisman 30/346.6 2,178,710 11/1939 Valiquette 30/349 2,582,913 1/1952 Pfefferle 30/346.58 2,627,656 2/1953 Richartz 30/254 3,349,488 10/1967 Graig.l 30/346.6 3,517,670 6/1970 Speelman 30/348 1/1971 Sheridan 30/344 4/1973 Taylor et al. 83/9155 Primary ExaminerDonald G. Kelly Assistant E.raminer-J. T. Zatarga Attorney, Agent, or Firm-Watson Leavenworth Kelton & Taggart 5 7] ABSTRACT A blade assembly designed for use in dermatone or skin grafting instruments in which the blade assembly is mounted on an oscillatory carrier, the blade assembly embodying a support or platform member of molded plastic to the forward edge portion of which is secured a metal blade element having a forward cutting edge, the support member having on its upper surface a plurality of raised ribs extending back at right angles to the cutting edge, the ribs serving to reinforce and give rigidity to the plastic support member and to guide and reduce the friction of engagement of the skin with the blade assembly, and the plastic support member having formed integrally therewith studs which in the assembly extend down through the blade element and are riveted over and avoid any projecting ends which could interfere with the free advance of the skin.

4 Claims, 4 Drawing Figures DERMATONE CUTTING BLADE ASSEMBLY GENERAL FIELD OF THE INVENTION The invention concerns a replaceable blade assembly for a skin grafting instrument commonly known as a dermatone. Typical examples of such an instrument are disclosed in the US. Pats. to Brown et al. No. 2,457,772 and Kratzsch et al. No. 3,428,045. As disclosed in this latter patent, the blade is removably secured to a supporting carrier which is oscillated by suitable power connections in guides parallel to the forward cutting edge of the blade and as the instrument is advanced a strip of skin is cut and advanced over the top surface of the blade.

As disclosed in the above patents, the blade is apparently a one piece element including a forward portion embodying the cutting edge proper and an integral rear portion with holes for securing it to the oscillatory carrier. In common practice the blade portions have been made of metal, the cutting edge element being of steel welded permanently to the metal supporting element.

THE PRESENT INVENTION The invention comprises a blade assembly which embodies a major blade supporting member of plastic to which is secured a blade element proper of stainless steel. The support member is provided on its upper surface with a plurality of raised ribs extending back at right angles to the cutting edge, the ribs serving to reinforce and give rigidity to the plastic support member and functioning to guide more freely the skin section over the surface of the blade assembly, reducing the friction of engagement of the skin with the blade assembly. The plastic support member has formed integrally therewith studs which in the assembly extend down through the blade element and are riveted over on the under surface thereby avoiding any upwardly projecting ends of locking elements which could interfere with the free advance of the skin over the blade assembly.

Other features and advantages will be made apparent from a consideration of an exemplary embodiment as described hereinafter and depicted in the drawings in which:

FIG. 1 is a view in perspective of the entire assembly of one form of the invention;

FIG. 2 is a cross-sectional view taken on the plane 11- of FIG. 1 and also FIG. 4;

FIG. 3 is a fragmentary section taken on the plane III- -III of FIG. 1; and

FIG. 4 is a somewhat modified form of the invention having features in common with the form of FIG. 1 but with additional rib elements and arranged somewhat differently.

The specific examples of the invention disclosed herein are intended as a replacement blade for a dermatone instrument similar to that shown in the above noted US. Pat. No. 3,428,045, and accordingly will have an overall structural shape and suitable openings for fastening elements to enable it to be secured on a power oscillated carrier like that shown in the patent. The blade assembly comprises as basic elements a support or platform member and a cutting blade ele ment 11 permanently secured thereto in the final assembly. The support member is composed of a suitable molded plastic material, a high impact styrene being particularly advantageous for the purpose; and the blade element 11 is of stainless steel having a forward sharpened edge 12. The blade element 11 fits into a recessed portion on the under surface of the support member 10 which has a rear shoulder 13 against which the straight rear edge of the blade element 11 engages for absorption of compression forces and provide stability.

As originally cast, the support member 10 is provided with a plurality of depending integrally cast studs 16, five such being indicated in FIG. 1. FIG. 3 shows the studs as originally cast comprising hollow elements being slightly tapered, decreasing in diameter toward the ends. In the final assembly, as indicated in FIG. 2, the ends of the studs are riveted over completely filling the holes in the blade element 11 and securely locking the rear edge of the blade against the shoulder 13 in the support member, and serving to resist the transverse shearing forces resulting from the oscillatory motion. By this form of securing elements the upper surface as indicated at 17 is free of any projecting bolt or riveted heads in the path of the advancing strip of skin.

As previously stated, the particular blade illustrated herein is designed to fit a commercial dermatone corresponding to that shown in the Us. Pat. No. 3,428,045. Accordingly the plastic member 10 has appropriate openings or holes for positioning and securing the blade assembly to the operating oscillatory carrier. These include the keyhole openings 18 for receiving locking studs and blind holes 20 extending upwardly from the lower surface for receiving locating or positioning pins. These features of course will vary depending upon the particular dermatone instrument the blade assembly is intended to fit.

Of major importancein the present blade assembly is the provision of ribs extending upwardly from the top surface of the support member 10. In the form of FIG. 1 there is shown a pair of ribs 22 projecting upwardly from the top surface of the support member 10 and extending in a generally right angle direction with respect to the blade cutting edge 12. The forward ends of the ribs 22 are formed with ramp portions 23 to encourage the free advance of the strip of skin over the ribs. The ribs 22 serve as reinforcements for the somewhat skeleton form of the support member 10 giving flat plane stability and also provide low friction guides for the strip of skin in its advance. Preferably also the surface has a transverse reinforcing rib 24 connecting the two rearwardly extending ribs 22 shown in the form of FIG. 1. Also the ribs serve to elevate the skin strip above the ends of locking bolts normally engaged in the keyholes opening 18. Between the ribs 22 the top surface of transverse rib 24 is lowered below the flow line of the skin on ribs 22 to avoid hang up of the skin at rib 24.

FIG. 4 shows a variation of the rib structure of the form of FIG. 1 but is generally similar in overall design to the form of FIG. 1. The support member 27 embodies a greater number of rib elements, there being five forward rib ramp portions 30 and four rearward rib portions 31 and a transverse rib portion 32. As in the form of FIGS. 1 and 2 the top surface of rib 32 is lowered below the top surfaces of ribs 31. Also added are end positioned ribs 33 and 34 with their individual forward ramp portions.

Being composed of plastic the support member lends itself readily to particular features such as being molded in different colors and having embossed or raised logo or other distinguishing data for coding and identification.

Various changes may be made in the blade assembly including different rib arrangements and openings in the support member dependent upon the circumstances and accordingly different embodiments of the invention made without departing from the scope thereof, and it is intended that all matter contained herein shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

l. A dermatone cutting blade assembly comprising a support member of moldable plastic and a blade element of metal having a forward cutting edge permanently secured to a forward edge part of said member, said member having raised ribs on its upper surface extending rearwardly transverse to said cutting edge, said ribs having ramps facing toward the cutting edge inclined upwardly and rearwardly to guide the skin.

2. A dermatone cutting blade assembly in accordance with claim 1 in which said blade element is secured to the under side of said forward edge part of said support member, the latter having a shoulder against which a rear edge of the blade element is engaged.

3. A dermatone cutting blade assembly in accordance with claim 1 in which said support member has holes for locking elements to secure the blade assembly to a carrier, said ribs being located and spaced to guide the skin above the locking elements.

4. A dermatone blade assembly in accordance with claim 1 in which said plastic support member has studs formed integrally therewith arranged to extend through holes in said blade element and being riveted over against the blade element. 

1. A dermatone cutting blade assembly comprising a support member of moldable plastic and a blade element of metal having a forward cutting edge permanently secured to a forward edge part of said member, said member having raised ribs on its upper surface extending rearwardly transverse to said cutting edge, said ribs having ramps facing toward the cutting edge inclined upwardly and rearwardly to guide the skin.
 2. A dermatone cutting blade assembly in accordance with claim 1 in which said blade element is secured to the under side of said forward edge part of said support member, the latter having a shoulder against which a rear edge of the blade element is engaged.
 3. A dermatone cutting blade assembly in accordance with claim 1 in which said support member has holes for locking elements to secure the blade assembly to a carrier, said ribs being located and spaced to guide the skin above the locking elements.
 4. A dermatone blade assembly in accordance with claim 1 in which said plastic support member has studs formed integrally therewith arranged to extend through holes in said blade element and being riveted over against the blade element. 